"It's absolutely epic. That's the best word I can put out there," Harper said.

Five of Washington's past six victories have been by a single run, with four coming in its last at-bat.

"It's been incredible," Harper said. "This team has a lot of fight, a lot of heart. We never die."

Harper opened the ninth with a single off Evan Marshall (4-3) and went to third base on Kevin Frandsen's one-out single. Out of the starting lineup for the first time in 63 games, Rendon singled past third baseman Cliff Pennington to win it.

"It was different to say the least, but it was awesome," Rendon said of the pinch hit.

Nationals: Williams sounded hopeful that 3B/OF Ryan Zimmerman could return "sometime in September" from a hamstring injury. Zimmerman was placed on the disabled list July 23.

Diamondbacks: In his fourth rehab appearance, Daniel Hudson tossed one scoreless inning with two strikeouts Tuesday night in the Arizona Rookie League. The right-hander hasn't pitched at the major league level since 2012 after sustaining an elbow injury that resulted in Tommy John surgery twice.